Watertight watchcase



Aug. 10, 1948. E. MORF 2,446,603

WATERTIGHT WATCHCASE Filed Jan. 27, 1945 I121) GIL-Z3010 $.JI01 f Patented Aug. 10, 1948 UNITED STATES PATENT OFFICE WATERTIGHT WATCHCASE Ernest Morf, La Chaux-de-Fonds, Switzerland Application January 27, 1945, Serial No. 574,849 In Switzerland October 23, 1944 1 Claim. 1

This invention relates to watertight watchcases.

There are watertight watch-cases, the center and bottom of which are in one piece, in that they are either forced into each other or Welded together, or made in one piece with each other. In such watches, a crystal of plastic material is forced into the combined center and bottom. Since in this case the quality of tightness depends on the pressure exerted on the inner walls of the combined center and bottom by the crystal of plastic material, and since, therefore, the crystal is given the greatest possible elasticity, removal of this crystal is so diflicult that, in spite of special precautions taken, it is very often damaged during this operation.

The object of the invention is to create a watch-case in which this danger of .damaging the crystal does no longer exist. Besides this, the characteristics of the invention allow various other advantages to be obtained, as will be seen later on. I

The watertight watch-case according to the invention comprises a crystal with a sleeve forced into the combined center and bottom and is characterised in that this crystal has a circumferentia-l flange extending towards the outside of the watch-case and overlapping a joint formed between a thinned rim of the combined center and bottom and a caseband adjusted to this thinned mm.

The accompanying drawing illustrates, by Way of example, one embodiment of the Watertight watch-case according to the invention.

The single figure is an axial section through this embodiment.

Referring now to the drawing, the combined center and bottom is designated by 10. It has, as usual, a flange II on which the plate of a watch movement (not shown) is supported. The upper part of the member III has a rim l2 into which a sleeve I3 is forced, obtained by moulding and made in one piece with the crystal M. An elastic ring l5 compensates, by pressing upon the sleeve [3, an eventual fatigue of the latter.

The combined bezel and caseband [6, to which the lugs ll'are fixed, comprises a flange l8 bearing against the thinned rim I2. A shoulder I9 is provided beneath the member IS on the combined center and bottom I0, against which for instance the blade of a knife can be inserted for separating the two pieces from each other. And since the crystal M overlaps the joint between the flange l8 and the rim I2 by a flange 1 outside the sleeve l3, the crystal can be removed by acting upon the combined bezel and caseband H5 in order to separate it from the combined center and bottom H). In this way the watch-case can be completely taken to pieces for removing the movement without touching the crystal, thus avoiding any damage of the latter.

I wish it to be understood that I do not desile to be limited to the exact details of construction shown and described, for obvious modificat-ions will occur to a person skilled in the art.

What I claim is:

In a watch-case, a combined center and bottom comprising a thinned upper rim and a shoulder, a crystal having a sleeve forced into said upper rim, a caseband supported on said shoulder and surrounding said thinned upper rim, said crystal having a flange outside said sleeve, covering said thinned upper rim and at least a part of said caseband, said combined center and bottom comprising a second shoulder beneath said caseband to allow a tool to be supported thereon for attacking said caseband to remove said crystal.

ERNEST MORF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,302,340 Morf Nov. 1'7, 1942 FOREIGN PATENTS Number Country Date 195,115 Switzerland Apr. 1, 1938 196,014 Switzerland May 16, 1938 

